Rollstand drive



March 8, 1966 o. v. DUTRO ETAL 3,239,161

ROLLSTAND DRIVE Filed Dec. 51, 1965 70 7/ LEX 30 INVENTORS.

ORV/LLE 1/- DUTEO .S'HERMA/V H. HEM JON United States Patent 3,239,161ROLLSTAND DRIVE Orvilie V. Dutro, 5068 N. Commonwealth, and Sherman if.llf-lewson, 6% Knight Way, both of La Canada,

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Filed Dec. 31, 1963, Ser. N0. 334,776 8 Claims. or. 242-751 Thisinvention relates to a rollstand drive. It is an object of thisinvention to provide a simple rollstand drive which dispenses elongatedmaterial such as a web of paper from a roll at a constant speed andconstant tension, both the speed and tension being adjustable.

It is necessary to keep a close control over the velocity at which thematerial is fed out of a rollstand in order that tension between theroll and a point of demand such as a printing press not increase to thepoint where the web is broken or decrease to the point where the rolloverruns the press and chokes it with slack material.

Because rolls of newsprint and the like are inherently somewhat out ofround, and decrease in weight as the material is unwound, themaintenance of close speed and tension control is quite diflicult.Numerous suggestions have been made as to means for providing thesecontrols, and generally have involved complicated mechanisms, oftenincluding friction brakes and the like, which require constantadjustment and which inherently vary in their physical effects frommoment to moment, which is undesirable.

It is an object of this invention to provide a rollstand drive whichpays out the material from a roll at a sensibly constant feed andtension, but which still utilizes simple components which are readilyadjustable even when the press is in operation.

A rollstand drive according to this invention is adapted to unwind thematerial from a journaled roll of material, and includes a flexibleroller which has a normal radius when the roller is free of externalunsymmetrical forces. The radius of this flexible roller is changeableby unsymmetrical forces exerted on the periphery thereof. Movablemounting means journals the flexible roller, and is adapted to move theroller toward and away from the roller material. Force means isconnected to the mounting means and is adapted to move the mountingmeans toward the roll with a variable, controllable force. Drive meansdrives the roller at a constant angular velocity, and control meanscontrols the force exerted by the force means and thereby adjusts theradius of the flexible roller where it is effective on driving theperiphery of the roll of material. The peripheral surface speed of theroll is thereby closely controllable, and is a function of the effectiveradius of the flexible roller at its tangent point with the rod, whichin turn is a function of the force exerted upon the flexible roller.

According to a preferred but optional feature of the invention, themounting means comprises a pivoted arm, and the force means comprises afluid motor adapted to pivot the mounting means and thereby the rollertoward and away from the roll whereby to vary the effective radius ofthe flexible roller.

The above and other features of this invention will be fully understoodfrom the following detailed description and the accompanying drawings inwhich:

FIG. 1 is a side elevation partly in schematic, and partly incross-section, notation showing the presently preferred embodiment ofthe invention;

FIGS. 2, 3 and 4 are schematic illustrations showing the effect of thevariability of effective radius of the flexible roller upon the angularvelocity of the roll of material;

FIG. 5 is a front view of a flexible roller suitable for use in theinvention; and

3,239,161 Patented Mar. 8, 1966 FIG. 6 is a partial right-hand end viewof FIG. 5 taken at line 6-6 of FIG. 5.

FIG. 1 illustrates the presently preferred embodiment of variable speedrollstand drive 10 according to the invention. The object of theinvention is to pay off material 11 from roll 12, which roll maycomprise various types of elongated material, a well-known example beinga roll of newsprint. The identity and width of the material being paidoff roll 12 is of no importance to the invention.

Roll 12 is mounted to a core shaft 13 which is rotatably supported injournal 14. Journal 14 is immovable, and is adapted to receive the coreshaft so that roll 12 can turn thereon. Journal 14', is rigidly held inplace by structure not shown.

Material 11 is led over idler rolls 15, 16 to a sensing loop 17, formedby dancer roller 18. It is thus led over a pair of infeed rollers 19,2%). The infeed rollers drive the material and exert the demand on therollstand drive for material to feed a mechanism which is to treat thematerial, such as a printing press. The infeed rollers are generallydriven directly by the press drive and are adapted to supply material atthe rate demanded by the press or other mechanism. It is the object ofthis invention to provide material at the proper tension and speed tomeet the demands of the mechanism which accomplishes the next operation,such as printing.

A flexible roller is mounted to a shaft 27 to which a sprocket 28 ispinned for driving the same. The flexible roller is shown in more detailin FIGS. 5 and 6, and may be of any desired length and in the event thatthe web of material 11 is quite wide, there may be a plurality of thesemounted to an extended shaft 27. The most convenient example is apneumatic or semi-pneumatic tire as shown in FIGS. 5 and 6. Preferablyit will be made of non-marking rubber with generally cylindricalperipheral sections 29 and axial grooves 30 which enable the sections 29to flex and contract somewhat. The grooves are not essentialeven a truecylindrical tire will work well in this device, but the fingers formedby the grooves appear to be somewhat superior in achieving a variableeffective radius.

Drive means comprises a chain 36 engaged to sprocket 28, sprocket 28forming a portion of the drive means. Chain 36 is also engaged to drivesprocket 37 which in turn is driven by a chain 38 or other means, whichis preferably connected to and driven by the machinery which exerts thedemand on the system such as a printing press. Therefore, the drivemeans will turn the flexible roller at a constant angular velocity whichis ordinarily directly proportional to the angular velocity of some partof the demanding mechanism.

Movable mounting means 49 comprises a pivoted arm 41 mounted by pin 42to a pivot plate 43. The movable mounting means thereby is adapted tomove the flexible roller toward and away from roll 12.

Force means 4-4- is interconnected between a pivot plate 45 mounted tobase structure 46 and arm 41. The force means preferably comprises afluid motor 48 which in its preferred embodiment comprises a cylinder 49and a double-ended piston-rod combination 50 whereby a pair of cylinderchambers 51, 52 are formed. When pressure is increased in chamber 52,the tendency will be for the piston rod to move to the left in FIG. 1,and force the flexible roller more firmly against the roll. When thepressure is increased in chamber 51, the tendency is the reverse.

Control means 55 is provided for controlling the operation of the forcemeans and derives its signal from the dancer roll through a support arm56 (of which there will ordinarily be a pair supporting the roll, onlyone of which need be connected to the control system itself).

Bias means 57 comprises a fluid motor 58 which is preferably a cylinder59 including a piston-rod combination 60, which rod is connected to thesupport arm. The piston divides the cylinder into chambers 59a and 59b.The support arm is attached to a pivot plate 61, which pivot plate ismounted to supporting structure. A cam 62 is also mounted to the supportarm and is effective upon the actuating pin 63 of a bleed-type pressureregulator 64. This pressure regulator is of the type which tends tomaintain an established pressure in its regulated conduit 65 (aregulated conduit being one which receives the pressure controlled by aregulator). The regulator is provided with an exhaust conduit 66 forexhausting fluid from the regulated conduit when pressure thereinexceeds the selected pressure.

Supply conduit 67 derives its source of fluid under pressure from pump68 which may conveniently include accumulators, not shown and otherstandard pneumatic equipment such as relief valves and the like. Pump 68also supplies a pair of bias circuits, one of which includes conduit 69which is directed to an adjustable bleedtype regulator 76 of the samegeneral type as regulator 64, and the regulated conduit 71 is connectedto chamber 59a of fluid motor 58. Chamber 5% of motor 58 is vented.

Conduit 75 connects still another adjustable bleed-type regualtor 76 tothe source of fluid under pressure, and regulated conduit 77 supplieschamber 51 of fluid motor 48. The bias circuits comprising regulatedconduits 71 and 77 exert a constant force within their respectivechambers. In the case of fluid motor 48, this bias pressure tends toretract the mounting means and to relieve pressure on roll 12. In fluidmotor 58, this exerts a constant biasing pressure on the dancer rollerwhich is opposed by tension in the sensing loop. The tension may beadjusted by changing the pressure derived from regulator 70, and thusvarying the downward force on arm 56. Gauge 79, connected to conduit 71may be calibrated to read in units of web tension.

As can be seen from an examination of FIG. 1, upward movement of thedancer roller permits cam 62 to allow actuating pin 63 to rise, becausepin 63 is spring-loaded by conventional means common to regulators ofthis type. Lowering of the dancer roller, which occurs when there is toomuch slack in the dancer loop causes the cam to depress the actuatingpin.

The object of the invention is to maintain tension and speed by keepingthe length of the sensor loop at about the position shown, at whichposition the relationship between the flexible roller and the roll isabout as shown in FIGS. 1 and 3. Should the mechanism demand paper at agreater rate, then tension Will be increased in the sensing loop, andthe dancer roll be raised. This means that the roll must be speeded up.Accordingly, the dancer roll will rise, as will the actuating pin. Theeffect of the pressure regulator 64 is to decrease the pressure inconduit 65 and chamber 52, permitting the flexible roller to movesomewhat away from the roll. Were the demand to be less, or the roll tobe overspeeding, then the sensor loop would slacken and lengthensomewhat, in which event the dancer roll would move downward, depressingthe actuating pin in which event the effect would be to raise thepressure in conduit 65 and chamber 52, pressing the flexible roller morefirmly against the roll. The bias pressure in chamber 51 assuresretraction when needed.

The effects of the aforesaid movements are as follows. Consider firstthe situation shown in FIG. 2, which is a limiting situation where theunflexed effective radius R of the flexible roller is shown tangent toan arbitrary radius R of the roll. This is the fastest ratio between theradii. The surface speeds of the two will be the same, and their angularvelocities will be inverse to their radii.

Assume now that the condition is as shown in FIG. 3, with the flexibleroller pressed firmly against roll 12 so that an unsymmetrical force isexerted which causes the radius to be reduced at the tangent point (andin limited regions on each side), then the effective radius will becomeroughly that shown as R instead of R Surprisingly, there appears to besufficient compensation within the material of these flexible rolls,particularly when they are grooved as in FIGS. 5 and 6, that it is theradius R which determines the relative angular velocities between theroll and the flexible roller. While it is not an absolutely linearrelationship, still it is sufficiently close, and definitely of suchproportionality that the effect is as described herein.

Next assume that the flexible roll is forced still more firmly againstroll 12, further reducing the effective tangential radius of theflexible roller to that shown in FIG. 4 as R R being less than R in thiscase the ratio of effective radii will be different from either of theforegoing.

The angular velocity of roll 12 (keeping in mind that the angularvelocity of the flexible roller is constant) is greater in FIG. 2 thanin FIG. 3, which in turn is greater than that in FIG. 4. FIG. 3therefore show a nominal equidistance point, with faster and slowerspeeds available on each side thereof. It will thereby be seen that byvarying the force on the mounting means, an unsymmerical force (the termunsymmetrical force being used in the sense of a force not beingcompletely continuous around the rollers, but one which is opposed onlyby the shaft of the roller) changes the effective driving radius andwith it the velocity of the driven roll. This device is simple, made ofeasily manufactured, and readily adjusted components, which have littlewear, and which works well. A heavy roll on the order of 1400 pounds canbe started up to full speed in a matter of only a few seconds, and thetension and the speed may thereafter be very closely regulated by thisdevice.

Additional versatility of control is attainable by varying the pressurein the flexible roller when a pneumatic roller is used, because then thechange in effective radius is proportional to an additional variabletheinflating pressure.

This invention is not to be limited by the embodiment shown in thedrawings and described in the description which is given by way ofexample and not of limitation, but only in accordance with the scope ofthe appended claims.

We claim:

1. In a rollstand drive adapted to drive a journaled roll of materialfor unwinding the material therefrom, a drive for the roll comprising: aflexible roller having a normal radius when it is free of externalunsymmetrical forces, said radius being locally changeable byunsymetrical forces exerted on the periphery thereof; movable mountingmeans journaling the flexible roller and adapted to move the flexibleroller toward and away from the roll of material; force means connectedto the mounting means adapted to move the mounting means toward the rollwith a variable, controllable force; drive means driving the roller at aconstant angular velocity; and control means controlling the forceexerted by the force means in response to tension in the unwoundmaterial, whereby the angular velocity of the roll of material varieswith the tangential radius of the flexible roller, which is a functionof the force exerted by the force means.

2. Apparatus according to claim 1 in which the flexible roller is apneumatic construction.

3. Apparatus according to claim 1 in which the control means comprises adancer roll responsive to tension in a loop of unwound material, and inwhich the force means is controlled as a function of the position of thedancer roller.

4. Apparatus according to claim 1 in which the control means comprises adancer roll responsive to tension in a loop of unwound material, ableed-type pressure regulator, cam means operated by the dancer roll andeffective to vary the pressure produced by the pressure 8. Apparatusaccording to claim 7 in which the periphregulator, the force meanscomprising a fluid motor acoral surface of the flexible roller isaxially grooved. tuated by the said pressure.

5. Apparatus according to claim 4 in Which bias means Referemes Clted ythe Exammel forces the dancer roller against said loop of material. 5 UND STATES PAT 6. Apparatus accord ng to clalm 5 1n which the has1,093,913 4/1914 Church 242 75 1 X means comprises a fluid motor and anad ustable-pres- 1972 676 9/1934 B I o za 242-751 sure bleed-typeregulator, the fluid motor tending to press 2 341 636 2/1944 Luehrs thedancermller againstthe 2:670:907 3/1954 Huck LII LII: 242 7s.1

7. Apparatus according to claim 6 in which the flexible 10 roller is apneumatic construction. MERVIN STEIN, Primary Examiner.

1. IN A ROLLSTAND DRIVE ADAPTED TO DRIVE A JOURNALED ROLL OF MATERIALFOR UNWINDING THE MATERAIAL THEREFROM, A DRIVE FOR THE ROLL COMPRISING:A FLEXIBLE ROLLER HAVING A NORMAL RADIUS WHEN IT IS FREE OF EXTERNALUNSYMMETRICAL FORCES, SAID RADIUS BEING LOCALLY CHANGEABLE BYUNSYMMETRICAL FORCES EXERTED ON THE PERIPHERY THEREOF; MOVABLE MOUNTINGMEANS JOURNALING THE FLEXIBLE ROLLER AND ADAPTED TO MOVE THE FLEXIBLEROLLER TOWARD AND AWAY FROM THE ROLL OF MATERIAL; FORCE MEANS CONNECTEDTO THE MOUNTING MEANS ADAPTED TO MOVE THE MOUNTING MEANS TOWARD THE ROLLWITH A VARIABLE, CONTROLLABLE FORCE; DRIVE MEANS DRIVING THE ROLLER AT ACONSTANT ANGULAR VELOCITY; AND CONTROL MEANS CONTROLLING THE FORCEEXERTED BY THE FORCE MEANS IN RESPONSE TO TENSION IN THE UNWOUNDMATERIAL, WHEREBY THE ANGULAR VELOCITY OF THE ROLL OF MATERIAL VARIESWITH THE TANGENTIAL RADIUS OF THE FLEXIBLE ROLLER, WHICH IS A FUNCTIONOF THE FORCE EXERTED BY THE FORCE MEANS.